title: Genetic engineering techniques for lactic acid bacteria: construction of a stable shuttle vector and expression vector for β-glucuronidase.
abstract: The shuttle vector, pUL6erm, was constructed by using a replicon from pL2, a multiple cloning site, colE1 ori, the ori of Gram-negative bacteria from vector pUC19, and the erythromycin resistance gene from pVA838 as a selection marker. pUL6erm could be transformed easily and maintained stably in Lactococcus lactis, Streptococcus thermophilus, Lactobacillus plantarum and Lactobacillus casei. Transformation assays of pUL6erm indicated that it had a narrow host range. β-Glucuronidase was induced in the presence of 0.3 M NaCl and 50 mM glutamate and expressed at 2.4 U mg(-1) with the expression vector (pUL6erm-gadR-GUS) constructed based on pUL6erm carrying β-glucuronidase gene wuth a chloride-inducible (gadR) expression cassette using Pgad as promoter. Therefore, pUL6erm and pUL6erm-gadR-GUS might be a safe and useful genetic tool for the improvement of lactic acid bacteria.
authors.affiliation: Institute of Bioengineering, Tatung University, Taipei, 104, Taiwan.
authors.forename: Shiao-Ming
authors.initials: SM
authors.lastname: Chang
authors.forename: Tsong-Rong
authors.initials: TR
authors.lastname: Yan
mesh_terms: D015870:Gene Expression; D005818:Genetic Engineering / Q000379:methods*; D005822:Genetic Vectors; D042822:Genomic Instability; D007778:Lactobacillus / Q000235:genetics*; D013294:Lactococcus lactis / Q000235:genetics*; D048249:Streptococcus thermophilus / Q000235:genetics*; D014169:Transformation, Bacterial